Molluscum contagiosum - External and Internal Eye
Molluscum contagiosum is a viral skin infection caused by a DNA poxvirus. It manifests as smooth, firm papules with a central umbilication. Molluscum contagiosum may be spread by direct contact (most often in children), autoinoculation, or via sexual transmission in adults. Molluscum contagiosum infections have also been associated with swimming pool facilities via fomites.
In adults, molluscum contagiosum is commonly distributed on the mons pubis, genitalia, perineum, inner thighs, and lower abdomen. The distribution in children is on the trunk and extremities.
Many cases are asymptomatic, but there can be surrounding irritation and pruritus.
In the immunocompetent host, the disease tends to be self-limited, but papules may persist for several months and up to 2 years before disappearing.
Patients with AIDS or who are otherwise immunosuppressed are at particular risk of molluscum infection, with reported prevalence rates of 5%-18%. Other risk factors are atopic dermatitis and sarcoidosis.
B08.1 – Molluscum contagiosum
40070004 – Molluscum contagiosum
Differential Diagnosis & Pitfalls
- Herpes simplex lesions can resemble molluscum with a central umbilication, but lesions are fluid-filled rather than solid as in molluscum contagiosum.
- Sebaceous hyperplasia primarily occurs on the face and has a whiter to slight yellow, lobular appearance.
- Warts tend to have a verrucous or jagged surface, whereas molluscum contagiosum lesions are smooth.
- Milia tend to be whiter in color and more concentrated on the face.
- Lobular capillary hemangioma (pyogenic granuloma) is obviously vascular with frequent ulceration.
- Lichen planus lesions are purple, pruritic, planar papules that can also spread in a linear pattern.
- Basal cell carcinoma tends to be solitary.
- Keratoacanthomas have a central keratin core and grow rapidly.
- Spitz nevus
- Large cell acanthoma
- Eyelid abscess
- Pigmented spindle cell and/or epithelioid cell nevus (see Spitz nevus)